I have experimented with various high temp clear coatings and found that most of them tend to yellow over time, and they have a hint of gloss to them. The only exception so far that I have found to that rule is the high temp satin "Diamond" clear product sold by Eastwood. When this product is applied in several very thin coats it has worked reasonably well and held up to several seasons of wear and driving to shows without being conspicuous.
The other alternative I've tried is the light application of a coating of WD40 a couple of times a year, and at the end of the season using a 0000 steel wool pad as the applicator. This is a very gentle application using the wool to knock loose any surface contaminents, followed by a wipe down with shop towel that leaves a hint of the oil in place.
It would be hard to imagine a ceramic coating applied with a true satin finish that would not be obvious.